Which type of cell relies exclusively on glucose for fuel?

Red blood cells rely exclusively on glucose for fuel due to their unique metabolic requirements and lack of mitochondria. Unlike many other cell types, red blood cells do not engage in aerobic respiration because they lack the necessary organelles to utilize oxygen for energy production efficiently. Instead, they rely on anaerobic glycolysis, a process that allows them to generate energy solely from glucose.

This reliance on glucose is critical as red blood cells are responsible for transporting oxygen throughout the body. The high demand for energy and the need to maintain their primary function of oxygen delivery necessitate their dependence on glucose as their sole source of energy. Other cell types have varying metabolic flexibility and can utilize different sources of energy, including fats and proteins, depending on their environment and specific functional roles.